The supplement was tested against a placebo on a hundred sufferers of mild to moderate osteoarthritis of the knee. After eight weeks, the Pycnogenol group reported a significant reduction in pain, and the benefits continued four and eight weeks later. They also had less stiffness in the joint, were able to carry out more daily activities, and could also reduce their use of painkillers, while 10 per cent in the placebo group had to increase their dose of analgesics.

(Source: Phytotherapy Research, 2008; 22: 1087-92).